The Beginning of the Universe and of Time

1996 ◽  
Vol 26 (2) ◽  
pp. 169-189 ◽  
Author(s):  
Richard Swinburne
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Material Objects ◽  
Causal Powers ◽  
Quantum Field ◽  
Physical Objects ◽  
Physical Cosmology ◽  
The Universe

What does it mean to say that the Universe had a beginning? There are different ways of spelling this out. I shall develop them, consider the logical relations between them, and support one as best capturing our intuitive understanding of this notion. I shall then draw a conclusion about whether Time could (it is logically possible) have a beginning. Finally I shall consider, on my preferred understanding of what it is for the Universe to have a beginning, what physical cosmology can show about whether it did in fact have a beginning.I understand by a Universe, a system of substances temporally connected to each other. I understand by a substance a thing with causal powers or liabilities, that is able to act or be acted upon. Substances will thus include both material objects and any other physical objects there may be such as chunks of energy or the fluctuating ‘vacuum’ of quantum field theory, and immaterial objects, if there are any, such as souls and ghosts. I understand by two substances being temporally connected that they exist for periods of time which are either earlier than, overlap with, or are later than each other.

scholarly journals The Dirac Sea, T and C Symmetry Breaking, and the Spinor Vacuum of the Universe

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 124
Author(s):  
Vadim Monakhov
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Symmetry Breaking ◽  
Momentum Space ◽  
Quantum Field ◽  
Conjugation Operator ◽  
Dirac Sea ◽  
Canonical Anticommutation Relations ◽  
The Universe ◽  
Dirac Conjugation

We have developed a quantum field theory of spinors based on the algebra of canonical anticommutation relations (CAR algebra) of Grassmann densities in the momentum space. We have proven the existence of two spinor vacua. Operators C and T transform the normal vacuum into an alternative one, which leads to the breaking of the C and T symmetries. The CPT is the real structure operator; it preserves the normal vacuum. We have proven that, in the theory of the Dirac Sea, the formula for the charge conjugation operator must contain an additional generalized Dirac conjugation operator.

Inhomogeneous solutions in cosmology

1990 ◽  
Vol 68 (9) ◽  
pp. 824-826
Author(s):  
Paul S. Wesson
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
General Relativity ◽  
Particle Physics ◽  
Quantum Field ◽  
Einstein’S Equations ◽  
Einstein's Equations ◽  
Cosmological Solutions ◽  
The Universe ◽  
Friedmann Robertson Walker

The standard cosmological solutions of Einstein's equations of general relativity describe a fluid that is homogeneous and isotropic in density and pressure. These solutions, often called the Friedmann–Robertson–Walker solutions, are believed to be good descriptions of the universe at the present time. But early on, processes connected with particle physics and quantum field theory may have caused localized inhomogeneities, and recently some new kinds of solution of Einstein's equations have been found, which may describe such regions. In one solution being studied by Wesson and Ponce de Leon (Phys. Rev. D: Part. Fields, 39, 420 (1989)), the density is still uniform but the pressure is nonuniform about a centre. The mass is given by a relation that looks like the familiar Newtonian relation m = (4/3)πR3ρ. However, the solution has other properties that are quite strange (e.g. a region of negative pressure and a kind of dipolar geometry). It is not known if solutions like this are merely mathematical curiosities or imply something about the behaviour of real matter in extreme situations.

Quantum Field Theory on the Universe Model of Closed Friedmann

1994 ◽  
Vol 11 (4) ◽  
pp. 193-196 ◽  
Author(s):  
Yougen Shen ◽  
Zongyi Cheng ◽  
Haogang Ding
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Field ◽  
Universe Model ◽  
The Universe

Quantum field theory of the Universe

1989 ◽  
Vol 39 (4) ◽  
pp. 1123-1129 ◽  
Author(s):  
Akio Hosoya ◽  
Masahiro Morikawa
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Field ◽  
The Universe

scholarly journals Creation of Particles in Cosmology

1974 ◽  
Vol 63 ◽  
pp. 329-333
Author(s):  
Ya. B. Zel'Dovich
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Mechanics ◽  
Stress Tensor ◽  
Particle Creation ◽  
Quantum Field ◽  
Energy Stress ◽  
The Creation ◽  
Physical Cosmology ◽  
The Impact

The creation of particles is a process which can only be described by quantum field theory. The old classical theories dealing with indestructible particles are incompatible with particle creation. It was the discovery of the corpuscular nature of light (Einstein, 1905) and the prediction of antiparticles (Dirac, 1929) which demonstrated that particle creation was possible. The creation of particles may influence the cosmological equations through the energy-stress tensor of these particles. For physical cosmology the particles themselves are important. Therefore this report deals with a particular example of the impact of quantum mechanics on cosmological theory.

Quantum field theory of the Universe in the Kantowski-Sachs space-time

1996 ◽  
Vol 111 (3) ◽  
pp. 327-330
Author(s):  
You-Gen Shen ◽  
Zhen-Qiang Tan
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Space Time ◽  
Quantum Field ◽  
The Universe

What Flashes Up: Theological-Political-Scientific Fragments

2017 ◽  
Author(s):  
Karen Barad
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Physics ◽  
Judith Butler ◽  
Quantum Field ◽  
The World ◽  
Karen Barad ◽  
Human Ethics ◽  
Realist Interpretation ◽  
The Universe

In “What Flashes Up,” Karen Barad exposes a startling new sense of matter. The “agential realist” interpretation of quantum physics in her monumental Meeting the Universe Halfway had already brought the indeterminacy and relationality—the “intra-activity”—of quantum ontology into resonance with human ethics: All beings compose and partake in the responsive structure of the world. “Intra-acting responsibly as part of the world means taking account of the entangled phenomena that are intrinsic to the world’s vitality and being responsive to the possibilities that might help us flourish.” In the present discussion, Barad draws Walter Benjamin’s messianic “now-time” via Judith Butler and quantum field theory into a deep meditation on the matter of time, a time that breaks from the scientific and political modernisms of purportedly linear progress.

scholarly journals Quantum Field Theory Representation in Quantum Computation

2021 ◽  
Vol 11 (23) ◽  
pp. 11272
Author(s):  
Nicolás Lori ◽  
José Neves ◽  
José Machado
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Mechanics ◽  
Quantum Computation ◽  
Quantum Computers ◽  
Quantum Field ◽  
Simple Manner ◽  
The Future ◽  
The Universe

Recently, from the deduction of the result MIP* = RE in quantum computation, it was obtained that Quantum Field Theory (QFT) allows for different forms of computation in quantum computers that Quantum Mechanics (QM) does not allow. Thus, there must exist forms of computation in the QFT representation of the Universe that the QM representation does not allow. We explain in a simple manner how the QFT representation allows for different forms of computation by describing the differences between QFT and QM, and obtain why the future of quantum computation will require the use of QFT.

scholarly journals STIMULATED CREATION OF QUANTA DURING INFLATION AND THE OBSERVABLE UNIVERSE

2011 ◽  
Vol 20 (14) ◽  
pp. 2861-2866 ◽  
Author(s):  
IVAN AGULLO ◽  
LEONARD PARKER
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
The State ◽  
Effective Theory ◽  
Quantum Field ◽  
Microwave Background ◽  
Observable Universe ◽  
Galaxy Distribution ◽  
Natural Mechanism ◽  
The Universe

Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when the corresponding stimulated creation of quanta is considered, the characteristics of the state of the universe at the onset of inflation are not diluted by the inflationary expansion and can be imprinted in the spectrum of primordial inhomogeneities. The non-gaussianities (particularly in the so-called squeezed configuration) in the cosmic microwave background and galaxy distribution can then tell us about the state of the universe that existed at the time when quantum field theory in curved spacetime first emerged as a plausible effective theory.

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